I have been trying to build aircraft switch covers for a while now. I found trying to print lettering just does not look good enough, however, a laser engraver does a great job. That still leaves the problem of contrasting color in the lettering. I made some that look great by painting a cover made from black nylon, then lasing off the paint. The paint does not hold up as well as I would like, though, so I came up with a new idea...
Has anyone tried to make an object with the outside layer a different color, (but of the same material)?
If that works, the laser should penetrate the outer layer white layer, leaving the lettering in black.

print the switch in black then paint it white and laser through the paint. i have never used a laser so im just guessing if that would work. if switches are printed in abs and you paint with a solvent base paint then it will bond like crazy without any prep.

That white lasered over black nylon looks like the way to. Jim has a very good point about bonding between paint and print. Make sure you are using a white lacquer and not an enamel. The acetone solvent will slightly soften the ABS and the paint will stick nicely.

The other thought would be to print in white and leave a small recess in the switch. Then you could print, paint, and laser a black filament insert and glue it into the switch recess.

You could also add fillets to the switch edges and it would help with the chipping vs. the sharp edges.

I made this by creating two files in SolidWorks from my original. All I did was use the "Offset" command 0.4mm/0.016". When I printed it/them, S3D actually made two passes of the white. This is made from PLA; I will try nylon later. Now, if the laser cuts through the white layer...